Ribbed convolution muffler



FIG. 1 is a perspective view of a ribbed convolution muffler depicting a new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a bottom plan view thereof;

FIG. 4 is a front view thereof;

FIG. 5 is a rear view thereof;

FIG. 6 is a left side view thereof; and,

FIG. 7 is a right side view thereof.

The dash-dash broken lines are included for the purpose of illustrating portions of the ribbed convolution muffler that form no part of the claimed design.

The ribbed convolution muffler is shown with symbolic breaks, and any portion of the ribbed convolution muffler between the dash-dot break lines forms no part of the claimed design. The dash-dot break lines form no part of the claimed design. 

CLAIM The ornamental design for a ribbed convolution muffler, as shown and described. 